Just thinking aloud: Uber doesn't actually run driver verification and background checks, they hire other companies for that. In a more decentralized world, drivers would pay for that service themselves and get a digitally-signed certificate that they could upload to the software. Same for being sued: the driver would have to get insurance or escrow a certain lump sum (and upload proof too), so that if someone sued and won, the money could be used to pay for that.